package org.apache.lucene.search.spans;

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.Term;
import org.apache.lucene.util.ToStringUtils;

import java.io.IOException;
import java.util.Set;

/** Matches spans containing a term. */
public class SpanTermQuery extends SpanQuery {
    protected Term term;

    /** Construct a SpanTermQuery matching the named term's spans. */
    public SpanTermQuery(Term term) {
        this.term = term;
    }

    /** Return the term whose spans are matched. */
    public Term getTerm() {
        return term;
    }

    @Override
    public String getField() {
        return term.field();
    }

    @Override
    public void extractTerms(Set<Term> terms) {
        terms.add(term);
    }

    @Override
    public String toString(String field) {
        StringBuilder buffer = new StringBuilder();
        if (term.field().equals(field))
            buffer.append(term.text());
        else
            buffer.append(term.toString());
        buffer.append(ToStringUtils.boost(getBoost()));
        return buffer.toString();
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = super.hashCode();
        result = prime * result + ((term == null) ? 0 : term.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (!super.equals(obj))
            return false;
        if (getClass() != obj.getClass())
            return false;
        SpanTermQuery other = (SpanTermQuery) obj;
        if (term == null) {
            if (other.term != null)
                return false;
        } else if (!term.equals(other.term))
            return false;
        return true;
    }

    @Override
    public Spans getSpans(final IndexReader reader) throws IOException {
        return new TermSpans(reader.termPositions(term), term);
    }

}
